1. Field of the Invention
The present invention relates to multiple strand twines comprising monofilaments and multiple filaments and fishnets produced therewith.
For example the present invention relates to multiple strand twines and fishnets formed of the multiple strand twines which find particularly advantageous use in the Alaskan fisheries where governmental regulations require that fishnets formed of synthetic twines have at least thirty (30) strands or filaments; but, wherein such multiple strand twines have heretofore commonly been formed of a plurality of equal diameter filaments, and, consequently, the resulting fishnets do not possess the desired characteristics of transparency or invisibility in water which is a requisite characterstic of such nets. Therefore, multiple strand twines and fishnets formed therewith have been eagerly desired which meet filament requirement established for the Alaskan fisheries and which possess the characteristics of transparency and invisibility in water.
2. Description of the Prior Art
It is usually required that twines for fishnets meet the characteristics of transparency and invisibility in water and are further characterized by (a) high flexibility, (b) possessing knots which are compact, stable and less prone to loosening, and (c) the ease and efficiency with which knots can be formed. The fishnets employed, for example, in the Alaskan fisheries are additionally required to use synthetic twines formed of at least thirty (30) strands or filaments. Inventions have heretofore been proposed to meet the afore-mentioned characteristics and conditions. For example, in U.S. Pat. No. 3,329,061, the patentee describes a twine comprising seven (7) strands, a twisted centercore formed of a plurality of 210 denier synthetic filaments, and six (6) external strands or filaments wrapped thereabout. While such multiple strand twines thus constructed do serve to meet the requirements in the Alaskan fisheries, they are relatively thick for the required strength because the strands about the centercore are shorter than the surrounding strands. For this reason, they do not serve to optimize the strength, transparency, and invisibility in water.
In U.S. Pat. No. 4,466,331 as a second example, the patentee describes a twine construction produced by twisting at least one strand formed by undertwisting a plurality of synthetic multiple filaments together with strands formed of monofilaments in the same twisting direction of the above. Although the multiple strand twines have eliminated the afore-mentioned disadvantages, they have unstable torque and a possibility of producing twist irregularities because they are formed of twisted multiple filament strands and untwisted monofilament strands. When relatively thicker monofilaments are compared with relatively finer multiple filaments, the latter are more readily separated from the twines due to the differences in their bending resistances, thus making the twine surfaces rough. Accordingly, the multiple filaments cannot constitute fishnets which form easy and efficient knots.